The present invent ion relates to a cylinder valve operating apparatus for an internal combustion engine.
U.S. Pat. No. 5,297,516 issued to HARA on Mar. 29, 1994 discloses a cylinder valve operating apparatus. This known apparatus comprises a camshaft with at least one set of cams including a first cam and a second cam, and a rocker arm supported by a rocker shaft and driven by the first cam for rotatable motion about the rocker shaft. A free cam follower is supported by the rocker arm and driven by the second cam for rotatable motion relative to the rocker arm. A lever is supported by the rocker arm and has a locked position wherein the lever is in driving engagemeat with the free cam follower to provide a positive motion connection between the free cam follower and the rocker arm and a released position wherein the lever is out of driving engagement with the free cam follower to provide relative motion of the free cam follower to the rocker arm. A hydraulic piston and a lever release spring cooperate with each other to control a shift of the lever between the locked position and the released position.
An object of the present invention is to improve the apparatus of the above type such that fail-free and noiseless shift of the lever between the locked position and the released position is ensured.